"CYCLOPENTANE CARBOXYLATE COMPOUNDS AND PROCESS FOR PREPARING THE SAME "

Abstract

The present invention discloses cyclopentane carboxylate compounds. The I-hydrocarbyl-2-acyloxy-cyclopentane carboxylates according to the invention have a general formula (I): wherein groups R1 , R2 and R3, which are identical or different, are independently selected from the group consisting of linear or branched C1-C2alkyl, C3-C20cycloalkyl, C6-C20aryl, C7-C20alkaryl and C7-C20aralkyl. The present invention also discloses a process as well as intermediate compounds for preparing the compounds of formula (I), and use of the compounds (I) as electron donor in the preparation of catalysts for propylene polymerization.

Full Text

Specification
Cyclopentane Carboxylate Compounds, Process and Intermediates for Preparing the Same and Use thereof
Cross Reference of Related Application
The present application claims priority based on Chinese patent application No. 200410086289.X, filed on October 29, 2004, which is incorporated herein by reference in its entirety and for all purposes.
Technical Field
The present invention relates to cyclopentane carboxylate compounds, to a process and intermediates for preparing the same, and to use thereof. More specifically, die present invention relates to l-hydrocaibyl-2-acyloxy-cyclopent2n.e carboxylate compounds (I), to process for preparing the same, to the intermediate .
Background Art
It has been known to use a Ziegler-Natta catalyst containing. a titaniinn compound and an electron donor compound supported on active magnesium halii e in olefin polymerization. US 4,544,717 teaches that stereospecificity of a catalyst axi be improved by introducing an electron donor compound into a solid component containing a titanium compound. EP 0 045 977 discloses a polymerization catalyst 1: having higher activity and stereospecificity, wherein phthalates are used as intern, 1 electron donor compound, silicone compounds containing at least one Si-OR (wherein R represents alkyl) are used as external electron donor compound, aluminum alkyls are used as cocatalyst.
Many electron donor compounds useful in the preparation of catalysts as well as catalysts for olefin polymerization comprising these donor compounds have been disclosed. For example, EP0361493 and EP0728'24 disclose 1,3-diether compounds, CN 11 05671 A discloses 1,3-diketone compou nd

CN1236372A and CN1292800 discloses specific substituted malonate compounds, W003022894 discloses diesters of maleic acid as electron donor compound. Additionally, CN1446787A and CN1490340A disclose y-acyloxy-substituted ether compounds having a formula (HI), and catalysts for propylene polymerization and exhibiting excellent performance can be prepared using said compounds as internal electron donor added during the preparation of solid component of catalytic system for olefin polymerization through a preparation process similar to that used in the preparation of N-Catalysts (trade name of polypropylene catalyst by Beijing Research Institute of Chemical Industry, SINOPEC, China).
(Figure Removed) However, known literatures disclose nether
l-hydrocarbyl-2-acyloxy-cyclopentane carboxylate compounds having a gaeral formula (I) as described hereinafter as well as a process for the preparation thereof nor use of the compounds of the formula (I) as electron donor in the preparation of catalysts for olefin polymerization.
Summary of the Invention
An object of the invention is to provide novel cyclopentane carboxfl&te compounds, i.e. l-hydrocarbyl-2-acyloxy-cyclopentane carboxylate compound of formula (I).
Another object of the invention is to provide a process for preparing the compounds of the formula (I) as well as the intermediates used therein.
Still another object of the invention is to provide use of said compounds h iie preparation of olefin polymerization catalysts, especially Ziftgler-Natta
polypropylene catalysts.
Detailed Description of the Preferred Embodiments
The cyclopentane carboxylate compounds according to the invention, l-hydrocarbyl-2-acyloxy-cyclopentane carboxylate compounds, have a structure represented by the general formula (I):

iso-butyl 1 -phenethyl-2-p-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-p-methylbenzyl-2-p-methylbenzoyloxy-cyclopentane carboxylate; methyl l-methyl-2-o-inethylbenzoyloxy-cyclopentane carboxylate; methyl l-ethyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; methyl l-n-propyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; methyl l-iso-propyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; methyl l-n-butyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; methyl l-iso-butyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; methyl l-n-pentyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; methyl l-iso-pentyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; methyl l-n-hexyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; melhyl l-cyclopentyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; methyl l-cyclohexyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
ethyl l-iso-propyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-n-pentyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-iso-pentyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-cyclopentyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-cyclohexyl-2-o-methylben2X)yloxy-cyclopentane carboxylate; ethyl l-phenyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-p-methylphenyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-phenethyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-p-methylbenzyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-methyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-ethyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; iso-buty] l-n-propyl-2-o-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl 1 -iso-propyl-2-o-methylbenzoyloxy-cyclopentane
iso-butyl l-n-butyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
iso-butyl l-iso-butyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
iso-butyl l-n-pentyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
iso-butyl l-iso-pentyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
iso-butyl l-n-hexyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
iso-butyl 1 -cyclopentyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
iso-butyl l-cyclohexyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
iso-butyl l-phenyI-2-o-methylbenzoyloxy-cyclopentane carboxylate;
iso-butyl l-p-methylphenyl-2-o-methylbenzoyloxy-cyclopentane carboxyiate;
iso-butyl l-benzyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
iso-butyl l-phenethyl-2-o-meuiylbenzoyloxy-cyclopentane carboxylate;
iso-butyl l-p-methylbenzyl-2-o-metfaylbenzoyloxy-cyclopentane carboxylate;
methyl l-methyl-2-m-methylbenzoyloxy-cyclopentane carboxylate;
methyl l-ethyl-2-m-methylbenzoyloxy-cyclopentane carboxylate;
methyl l-iso-pentyl-2-m-melhylbenzoyloxy-cyclopentane carboxylate; methyl l-n-hexyl-2-m-methylbenzoyloxy-cyclopentane carboTfylate; methyl l-cyclopentyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; methyl 1 -cyclohexyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; methyl l-phenyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; methyl l-p-methylphenyl-2-m-methylbenzoyloxy-cyclopentane carboxylate methyl l-benzyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; methyl l-phenethyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-methyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-ethyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-isb-propyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-n-pentyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-iso-pentyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-cyclopentyl-2-m-methylbenzoyloxy-cyclopentane carboxylate;
ethyl l-cyclohexyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-phenyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-p-methylphenyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-phenethyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; ethyl l-p-methylbenzyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-methyl-2^m-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-ethyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-n-propyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-iso-propyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-n-butyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-iso-butyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-n-pentyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-iso-pentyl-2-m-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-o-hcxyl-2-m- iso-butyl l-ben2yl-2-m-methylbenzoyloxy-cyclopentane carboxylate; iso-butyl l-phenethyl-2-m-methylbenzx)yloxy-cyclopentane carboxylate; iso-butyl l-p-methylbenzyl-2-m-methylbenzoyloxy-cyclopentane carboxyl.
The process for preparing l-hydrocarbyl-2-acyloxy-cyclopentane compounds of the formula (I) according to the invention comprises, in turn, of:
1) synthesizing 2-hydrocarbyl-2-hydrocarbyloxycarbonyl-cyclopentc3ol intermediate having a general formula (n) (Figure Removed)
wherein R1 and R2 are as defined in the general formula (I) and X represents halogen
atom, by hydrocarbylating 2-oxocyclopentane carboxylate on a-carbon with a
halohydrocarbon (R2X) in the presence of a base and an aprotic solvent to form
l-hydrocarbyl-2-oxocyclopentane carboxylate, and then selectively reducing the
l-hydrocarbyl-2-oxocyclopentane carboxylate to form
2-hydrocarbyl-2-hydrocarbyloxycarbonyl-cyclopentanol (also known as l-hydrocarbyl-2-hydroxy-cyclopentane carboxylate) of the formula (II); and
2) synthesizing l-hydrocarbyl-2-acyloxy-cyclopentane carbpxylate compound of the formula (I)
(Figure Removed)aprotic solvent through conventional acylating methods (see, for example, Vogel's Textbook of Practical Organic Chemistry 5th ed., 1988), to form the corresponding 1 -hydrocarbyl-2-acyloxy-cyclopentane carboxylate compound of the formula (I).
The starting material, 2-oxocyclopentane carboxylate, used in the step 1) may be prepared through known synthesis methods disclosed in the literatures (see; for example, Org. Synth., Coll. Vol.,2,116(1943)).
In the step 1), a phase-transfer catalyst may or may not be used depending on the kind of the used halohydrocarbon (R2X). When the halohydrocarbon (R2J)tised in the hydrocarbylation on the a-carbon is a branched- or cyclic group-coniaiing haloalkane, phase-transfer catalyst, such as benzyl triethyl ammonium chioride, tetra-n-butyl ammonium bromide or combination thereof, is preferably usai. In general, known operation methods for hydrocarbylation on carbon atom the method disclosed in Tetrahedron 32, 2979 (1976)) can be followed with c solvent used. The aprotic solvent is preferably selected from the consisting
acetone; N,N-dimethyl formamide; dimethyl sulfoxide; tetrahydrofuran; aliphatic hydrocarbons, such as pentane and hexane; and aromatic hydrdcarbons, such as benzene, toluene, and xylene; and combination thereof, and more preferably aprotic polar solvents, such as acetone; N,N-dimethyl formamide; dimethyl sulfoxide; and combination thereof. The base is preferably selected from the group consisting of an alkali metal, an alkaline earth'metal, a hydride of alkali metal or alkaline earth metal, a carbonate of alkali metal or alkaline earth metal, and combination thereof, and more preferably a carbonate of alkali metal.
In the hydrocarbylation on the a-carbon of the step 1), molar ratio of the 2-oxocyclopentane carboxylate to the halohydrocarbon (R2X) is preferably in a range of from 1 : 0.5 to 1 : 5, and more preferably from 1 : 1 to 1 : 2; and molar ratio of the 2-oxocyclopentane carboxylate to the base is preferably in a range of from 1 : 05 to 1 : 5, and more preferably from 1 : 1.2 to 1 : 3. Reaction pressure is preferably in a range of from atmosphere pressure to 3 atm, and more preferably atmosptere pressure. Thereactk>oisr^ferablycarriedoutatateniperatureof from 10 to 19C°C, and more preferably from room temperature to 60 °C. Reaction time is prefccabV" in a range of from 1 to 24 boms, and the exact reaction tune can be detenninec by GC-MS analysis on the reaction liquid.
In the step 1), the l-hydrocarbyl-2-oxocyclopentane carboxylate obtained^ an be reduced by a reducing agent in an alcoholic solvent, to further form a compoi nd of the general formula (II). The used reducing agent can be selected from the gn~up consisting of metal borohydrides, such as lithium borohydride, sodium borohydicie, potassium borohydride, and zinc borohydride; aluminum alkOxides, such as aluminum isopropoxide; and combination thereof. More preferably, if a trcal borohydride is used, then sodium borohydride or potassium borohydride as wel as methanol solvent is preferably used; and if an aluminum alkoxide is used, t^n aluminum isopropoxide as well as iso-propanol solvent is preferably used.
In the reduction reaction of the step 1), molar ratio of l-hydrocarbyl-2-oxocyclopentane carboxylate to the reducing agent is preferably a range of from 1 : 0.5 to 1 : 2, and more preferably from 1 : 1 .2 tp 1 : 2. pressure is preferably in a range of from atmosphere pressure to |3 atm, and re preferably atmosphere pressure. The reaction is preferably cjarried out

temperature of from -20 to 100 °C, and more preferably from -10 to 78 °C. Reaction time is preferably in a range of from 0.1 to 10 hours.
If the reduction reaction employs sodium borohydride as reducing agent and methanol as solvent, the reaction is carried out at a temperature of from -20 to 65 °C, and preferably from -10 to 40 °C; molar ratio of the l-hydrocarbyl-2-oxocyclopentane carboxylate to sodium borohydride is preferably in a range of from 1 : 1 to 1 : 2, and more preferably 1 : 1.2; reaction pressure is preferably in a range of from atmosphere pressure to 3 atm, and more preferably atmosphere pressure; the reactants are preferably added in such a way that sodium borohydride is batchwise added to a solution of l-hydrocarbyl-2-oxocyclopentane carboxylate in methanol, and reaction time is preferably in a range of from 0.5 to 2 hours.
In the step 1), the l-hydrocarbyl-2-oxocyclopentane carboxylate obtained can also be selectively reduced in a solvent under catalytic hydrogenation conditions, to form a compound of me general tbnmla (D) (see, for example, J. Fuhihop, G Penzlin, Organic Synthesis-Concepts, Methods, Starting Materials, veriag chenue, 90,
>
1983). The used catalyst contains gpaenUy a liausitioa metal dement, and an be, selected from me group consisting of oickei-oontaiQing catalysts such as feney nickel, palladium-containing catalysts, Adams' catalyst, and rath^nium-contaaxing catalysts. Adams' catalyst is preferred. Reaction pressure is preferably in a range of from 1 to 10 atm, and more preferably from 1 to 3 atm. The reaction is prefsairiy carried out at a temperature of from 0 to 200 °C, and more preferably from 10*0 to room temperature. The solvent is preferably alcohols (for example, methanol, etknol, etc.), ethers (for example, tetrahydromran, 1,2-dimethoxy ethane* etc.), and (for example, ethyl acetate, butyl acetate), or combination thereof, and preferably ethanol. Depending on activity of a prepared catalyst and amount of tie catalyst, reaction time is preferably from 0.5 to 24 hours. The catalyst is geneaJ.ly used in an amount of from 0.1 to 5 percent by mole with respect to the reactant.
In the step 2), according to conventional acylation processes, the interme^te
(Figure Removed)presence of an acid (wherein R3 is as defined in the general formula (I); and X represents Cl, Br or I), to form l-hydrocarbyl-2-acyloxy-cyclopentane carboxylate compound. The acylating agent is preferably acyl halide. The niolar ratio of the acylating agent to the intermediate (II) is preferably in a range of from 1:1 to 15:1; and more preferably from 1.5:1 to 5:1. The base is preferably pyridine or trifthyl amine, and molar ratio of the base to the acylating agent is preferably in a rangs of from 1:1 to 10:1, and more preferably from 1:1 to 3:1. The solvent used in the acylation reaction is generally aprotic solvent, and can be selecte4 from the go up consisting of pyridine, tetrahydroruran, haloalkanes (such as methylene chloide, chloroform, etc.), aliphatic hydrocarbons (such as pentane, hexane, etc.) a.nd aromatic hydrocarbons (such as benzene, toluene, xyieoc, etc.), and combin&on thereof, with methylene chloride and chloroform being preferred Read on tenieperatiireisrjrcfei^ly marangeofrrom-20to200°C, and preferably from - to 100°C In the step 2), reaction pressure is preferably in a range of from atmospeie
If an acid anhydride is used as the acylating agent, the acylation reactioi is carried out in the presence of an acid catalyst, and commonly used acid catafets include sulfuric acid, zinc chloride, etc., with a catalytic amount of sulfuric e id being preferred (see, for example, Vogel's Textbook of Practical Organic Cheirat :ry 5th ed., 1988).
The lasting time of the acylation reaction can be varied or adjusted depenhig on the used intermediate (II) and the acylating agent, and the reaction canine monitored by thin-layer chromatography. Upon the completion of the readier*, l-hydrocarbyl-2-acyloxy-cyclopentane carboxylate compound of formula (I) obtained through conventional separation and purification processes, extraction, distillation, crystallization, recrystallization, thin-layer chromatograjHy, or column chromatography.
Among the intermediates used in the synthesis of the compouncs of the geits^l formula (I), the following 2-hydrocarbyl-2-hydrocarbyloxycarbonyl-cyclopenU>^l

compounds:
(Figure Removed)wherein R1 is C-Calkyl; R2 is selected from the group consisting of methyl; propyl and benzyl, are novel compounds synthesized by the inventors.
Such novel intermediates are, for example,
2-ethyl-2-ethoxycarbonyl-cyclopentanol;
2-n-butyl-2-ethoxycarbonyl-cyclopentanol;
The present invention is also directed to use of
l-hydrocarbyl-2-acyloxy-cyclopentane carboxylate compounds of the formula (T) in
the preparation of catalysts for olefin polymerization, such as Ziegler-Natta type
polypropylene catalysts. When used as electron donor in the preparation of
Ziegler-Natta catalysts for olefin polymerizaa on,
l-hydrocarbyl-2-acyloxy-cyclopentane carboxylate compounds of the fonnuh (I) exhibit excellent performance in enhancing activity and stereospecificity of the catalysts in polymerization. Said compounds are particularly suitably used as infernal electron donor in the preparation of spherical polypropylene catalyst.
Examples
Examples 1-12 Preparation of l-hydrocarbyl-2-oxocyclopentaiie carboxylav by hydrocarbylating on ct-carbon
Example 1 Methyl l-benzyl-2-oxocyclopentanecarboxylate
29.0 grams of anhydrous potassium carbonate and 132 ml of acetone were mixed, then with stirring, to the resulting mixture was dropwise added a solution of 13.0 ml of methyl 2-oxocyclopentane carboxylate in 66 ml of acetone. After stirring at room temperature for 30 minutes, 13.7 ml of benzyl bromide was dropwise added thereto, and the reaction was allowed to continue under reflux for 6 hours. Then the reaction mixture was cooled to room temperature, filtered, and concentrated, and 150 ml of toluene was added thereto. The resulting solution was washed with water (3 x 150 ml), dried over anhydrous sodium sulfate, concentrated, and distilled under reduced pressure. 13.4 g of colorless liquid as a distillate cut of 161-1 62°C/4.8 mmHg was collected. Yield: 55.1%.
'H NMR(400 MHz, CDC13): 1.60-2.44 (m, 6a 3CH2), 3.16 (dd, 2H, CHrPh, J=13.6 Hz), 3.72 (s, 3H, OCH3), ZU-7.14(m, 2H, AiH), 7J20-730(iii, 3H, Aifl).
Example 2 Ethyl 1 -benzyl -2-oxocydopentane carboxylate
38.7 grams of anhydrous potassnun catlmuate mad 90 ml of acetone were inked, then with stirring, to the resulting mixture was dropwise added a solution of 10.4 xnl of ethyl 2-oxocyclopentane carboxylate in 45 ml of acetone. After stirring at room temperature for 35 minutes, 16.7 ml of benzyl bromide was dropwise added tberrto, and the reaction was allowed to continue under reflux for 3 hours. Then the reaction mixture was cooled to room temperature, filtered, concentrated, and distilled mcLer reduced pressure. 11.54 g of colorless liquid as the second distillate Cut was colect
'H NMR(400 MHz, CDC13): 1.26 (t, 3H, CH3, J=7.2Hz), 1.50-2.50 (n, 3CH2), 3.16 (dd, 2H, CHjPh, J=13.6Hz), 4.18 (q, 2H, OCH2, J=7.2Hz), 7.1 l-5H,ArH).
Example 3 Ethyl 1 -methyl -2-oxocyclopentane carboxylate
Under vigorously agitation, 20.3 g of ethyl 2-oxocyclopentane carbo was added to 53.8 g of fine powdery anhydrous potassium carbjonate, stirring for several minutes, to the mixture was added 90 ml of acetone.
mixture was further stirred for 15 to 30 minutes at room temperature, then to the mixture was dropwise added 36.9 g of methyl iodide. Upon the completion of the addition, the reaction mixture was heated for reflux for 1 hourj The solvent was removed under reduced pressure, and the solid residue was washed with diethyl ether. The washing liquor was collected and washed with water. After removing the solvent, 22.0 g of pale yellow liquid was obtained. The liquid was distilled under reduced pressure, and 20.9 g of colorless liquid as a distillate cut of 131-133°C/39 mmHg was collected. Yield: 94.6 %.
!H NMR(400 MHz, CDC13): 1.25 (t, 3H, CH2CH3), 1.31 (s, 3H, CH3), 1.85-2.53 (m, 6H, 3CH2), 4.16 (q, 2H, OCH2).
Example 4 Preparation of ethyl l-ethyl-2-oxocyclopentane carboxylate
Under vigorously agitation, 31.2 g (purity of 90%,) of ethyl 2-oxocyclopenta.ne carboxylate was added to 76.04 g (party of 98%) of ground anhydrous potassium carbonate, and after storing for several minutes, to the mixture was added 100 nl of acetone. The reaction mixture was further stirred for about 15 minutes, then tt the mixture was dropwise added 29.51 ml (parity of 98 J%) of ethyl iodide. Upoi the completion of the addition, the reaction nnxtnre was heated for reflux for 5 hois; The reaction mixture was filtered under the reduced pressure, and the filter cake^as washed with diethyl ether until its color was purely white. Pale yellow filtrates as collected and dried over anhydrous magnesium sulfate, then the solvent was remtv^ ed. The residue was distilled under reduced pressure, and 32.03 g of colorless liquidi-s a distillate cut of 130-134°C/18 mmHg was collected. Yield: 96.7%. MS: m/e 156(M* -C2H5),140(NT- OCH2CH3), 139,101(1-CO2CH2CH3), 127(15 S-111(156-OCH2CH3), 55(base).
ffi. (film,cm-1): 2965(?MCH3), 2873, 1755(K>O), 1724(K)-C=O), (X>O-C).
Example 5 Preparation of methyl l-ethyl-2-oxocyclopentane carboxylate
Under vigorously agitation, 14.8 g of methyl 2-oxocyclopentane was added to 41.9 g of fine powdery anhydrous potassium carbonate, and stirring for several minutes, to the mixture was added 100 ml pf acetone.
reaction mixture was further stirred for 15 to 30 minutes at room temperature, then thereto was dropwise added 31.2 g of ethyl iodide. Upon the completion of the addition, the reaction mixture was heated for reflux for 2 hours. The solvent was removed under reduced pressure, and solid residue was washed with diethyl ether. The washing liquor was collected and washed with water. After removing the sol vent, 18.0 g of pale yellow liquid was obtained. The liquid was distilled under reduced pressure, and 15.9 g of colorless liquid as a distillate cut of 122-124°C/25 minHg was collected. Yield: 93.5%.
1HNMR(400 MHz, CDC13): 0.90 (t, J=7.5 Hz, 3H, CH2CH3), 1.61-2.40 (m 8H, 4CH2), 3.71 (s, 3H, OCH3).
Example 6 Ethyl l-n-butyl-2-oxocyclopentane carboxylate
Under vigorously agitation, 52.0 g (parity of 90%) of ethyl 2-oxocyclopeoiane carboxylate was added to 126.73 g (parity of 98%,) of ground anhydrous potassium carbonate, and after storing for several minutes, totbemixture was added 100 nil of acetone. Hie reaction mixture was farther stmed for about 15 minutes, men was dropwise added 66.0 ad (parity of 98%,) of l-broroo-o-botaDe, Upon the completion of the addition, the reaction mixture was heated for reflux for 5 hex xs. The reaction mixture was filtered under the reduced pressure, and the filter cab v as washed with diethyl ether until its color was purely white. Pale yellow filtrate v as collected and dried over anhydrous magnesium sulfate, then the solvent was The residue was distilled under reduced pressure, and 53.39 g of colorless liquid & a distillate cut of 140-141°C/16 mmHg was collected. Yield: 83.9%. MS: m/e 197CM4"- CH3), 184(M*--CH2CH2), 167(M*-OCH2CH3), IS^ 139(M*-CO2CH2CH3), 127, 111, 55.
'H NMR(400 MHz, CDC13): 0.89(t, 3H, (CH2)3CH3), 1.26(t, 3H, 1.23 -2.54(m, 12H, 6CH2), 4.16(q, 2H, OCH2).
Example 7 Ethyl l-iso-butyJ-2-oxocyclopentane carboxylate
Under vigorously agitation, 13.9 g of ethyl 2-oxocyclopentane added to 33.4 g of fine powdery anhydrous potassium carbonate and 1.14g o

triethyl ammonium chloride. After stirring for several minutes, to
the mix
added 60ml of N,N-dimethyl formamide and 21. 9g of iso-bury] bromide- Upon the completion of the addition, the reaction was heated to 55 °C and allowed to continue for 6 hours with stirring. The solvent was removed under reduced pressure, and solid residue was washed with diethyl ether. The washing liquor was collected and washed with water, and removing the solvent gave a crude product. The crude product was distilled under reduced pressure, and 15.3 g of colorless liquid as a distillate cut of 139-142°C /ISmmHg was colleted. Yield: 90.0%.
'H NMR(600 MHz, CDC13): 0.89(q, J=6.9 Hz, 6H, CH(CE02), 1.42(q, J=6;9 Hz, 1H ), 1.27 (t, J=6.9 Hz, 3H, OCH2CH3), 1.66-2.68 (m, 8H), 4. 12-4.21 (m, 2H, OCH2CH3).
Example 8 Ethyl l-n-hexyl-2-oxocyclopentane carboxylate
Under vigorously agitation, 31.2 g of ethyl 2-oxocyclopentanb carboxylate v/as added to 84.5 g (purity of 98%) of ground anhydrous potassium carbonate, and alter stirring for several "««mfr3?, to the mixture was added 100 ml of acetone, The reaction mixture was farther stirred for about 1 5 minutes, then thereto was dropsvise added 57.34 ml (purity of 98%) of completion of the addition, Ac reaction mixture was heated for reflux for 5 hours. The reaction mrtrure was filtered under the reduced pressure, and the filter cake was washed with diet hyl ether until its color was purely white. Pale yellow filtrate was collected and aried over anhydrous magnesium sulfate, then the solvent was removed! The residue was distilled under reduced pressure, and 41 .89 g of colorless liquid as a distillate cut: of 156-160 °C/23 mmHg was collected Yield: 87.3%. MS m/e 1223(K:-0-C).
Example 9 Ethyl l-p-methylbenzyl-2-oxocyclopentane carboxylate
Under vigorously agitation, 39.0 g of ethyl 2-oxocyclopentane carboxylafc^as added to 105.6 g (purity of 98%) of ground anhydrous potassium carbonate, awf^er stirring for several minutes, to the mixture was added 100 ml of acetone p 'he

completion of the addition, the reaction mixture was heated for reflux for 6 hours. The reaction mixture was filtered under the reduced pressure, and the filter cake was washed with diethyl ether until its color was purely white. Pale yellow filtrate was collected and dried over anhydrous magnesium sulfate, then the solvent was removed. The residue was distilled under reduced pressure, and 36.42 g of colorless liquid as a distillate cut of 156-162°C/22 mmHg was collected. Yield: ^9.52%. MS: m/e 227(M*"+1), 226(M4'"), 198,181,169,156,141,127,110, 95.
Example 12 Ethyl l-iso-pentyl-2-oxocyclopentane carboxylat4
Under vigorous agitation, 34.67 g (purity of 90%) of ethyl 2-oxocyclopentane carboxylate was added to 112.65 g (purity of 98%,) of ground aiirydrous potassium carbonate, and after stirring for several minutes, to the mixture was added 100 ml of acetone. The reaction mixture was further stirred for about 15 minutes, then thereto was dropwise added 5136 ml (purity of 98%) of 1-bromo-iso-pentane. Upon the
*
completkm of the addition, die reaction mnctme was heated lor reflux for 6 hours,
The reaction mixtore was fitted imdertitt was
washed with dkdiyl edicr until its ooior was purely white. Pate ydlow filtrate was collected and dried over anhydrous magDesransolf^ then u^sorvent was renoved.
The residue was distilled under reduced pressure, and 32.80 g of colorless liquid as a distillate cut of 142-147°C/15 mmHg was collected. Yield: 72.60%. MS: rn/e 2270^+1), 226(M*), 211^-013), ^SOvf-CHzCHz), 171 (MJ'-OCKbCHa), 156 (NT-CsH,,, base), 153(M*-CO2 CH2CH3), 127(155-CH2CH2), 1}1(156-OCH2(JH3), 55.
IR (film, cm'1): 2957(vaaCH3), 2871(vasCH2), 1752(vMOO)| 1721(v8SO-C=O), 1222(vasC-0-C).
Example 13-22 Preparation of 2-hydrocarbyl-2-hydrocVbyloxycarbvayl-
I
cyclopentanol intermediate (also known 4s 1-hydrocr^yl-
2-hydroxy-cyclopentane carboxylate) by reduction reaction

240 ml of methanol, and to the solution was added 5.28 g of ^nhydrous calcium chloride. The reaction mixture was cooled to about 0 °C using ari ice-salt bath, then 1.08 g of sodium borohydride was slowly and batchwise added with stirring, and additional 0.1 g of sodium borohydride was added to the mixture. The reaction mixture was stirred for further 30 minutes and then concentrated to give a white slurry. To the slurry were added 100 ml of methylene chloride and 100 ml of saturated aqueous solution of ammonium chloride. Organic layer was separated, washed with distilled water for three times, dried over anhydrous sodium sulfate, filtered and concentrated to give 4.42 g of pale yellow oil. MS: 249(M*"-H), 24S(M~), 230^-012012), 22Q(M*"-K2O), 184, 174, l57(M"-CH2C^lsl 145, 129, 115,91(fCH2C6H5,base),77.
1R (film,cm !): 3482(vOH), 1715(vO-C=O), 1 187(vC-O-C).
27.6 grams of ethyl l-eriivl-2-Qxocyclopentane carboxylate obtained from
Example 4 were weighed into a one-neck flask and then diluted using 60ml of dry
methanol. Then to the nuxtra« was added 34.69g of anhydnxisc and
the reaction mixture was stirred at room temperature for 30 minuses to give a c 1 ear solution. The temperature of reaction mixture was reduced to alJK)ut 0°C using an ice-salt bath, and 6.9 Ig of sodium borohydride was batchwise added. The leaction was stirred for 30 minutes, and then the solvent was removed. The residue was extracted using diethyl ether and water, then the organic phase was dried. Renov ing the solvent gave 25.19g of colorless liquid. MS: m/e 1^8(M**-H2Q, 158 (M*-CH2ai2), 157(M+--CH2CH3), Ml^-OOfeOIa), 129(base), 115, 113, '01
IR (film.cin1): 3482(vOH), 1726(K)-C=O), 1221(K)-C=O).
Example 16 2-n-butyl-2-ethoxycarbonyl-cyclopentanol (or
1 -n-butyl-2-hydroxy-cyclopentane carboxylate)
8.48 grams of ethyl l-n-butyl-2-oxocyclopentane carboxylate obtained Example 6 were weighed into a one-neck flask and then diluted using 60m]oJc-3rv methanol. Then to the mixture was added 9.25g of anhydrous calcium chlori

31.2 grams of ethyl l-p-methylbenzyl-2-oxocyclopentane caifboxylate obtained from Example 9 were weighed into a one-neck flask and then diluted using 60ml of dry methanol. Then to the mixture was added 27.75g of anhydrou^ calcium chloride, and the reaction mixture was stirred at room temperature for 30 minutes to give a clear solution. The temperature of reaction mixture was reduced to about 0°C using an ice-salt bath, and 5.53 g of sodium borohydride was batchwise added. The reaction was stirred for 30 minutes, and then the solvent was removed. The residue was extracted using diethyl ether and water, then the organic phase was dried. Removing the solvent gave 29.56 g of colorless liquid. MS: m/e 262(M+'), 244(Mt--CH2CH2), 234(M"-H2O), 216, 205, 198, 188, 171, 159, 157(M*- CH2C6H5), 145, 143, 131, 129, 115, 105(base), 91,77.
IR (film, cm'1): 3470(vOH), 1718(vO-C=O), 1188 (vC-O-C).
l-n-propyl-2-hydroxy-cyclopentane carboxyjate)
29.70 grams of ethyl 2-oxo-l-n-propyl-cyclopentane carboxytate were weighed into a one-neck flask and then diluted using 60ml of dry methanol. Then to the mixture was added 34.69 g of anhydrous calcium chloride, and thte reaction rnkture was stirred at room temperature for 30 minutes to give a clear solution The temperature of reaction mkture was reduced to about 0°C using an ice-salt batt, and 6.91 g of sodium borohydride was batchwise added. The reaction was stirred for 30 minutes, and then the solvent was removed. The residue was extracted using cfcthiyl ether and water, then the organic phase was dried. Removing the solvent gave 27 , 24 g of colorless liquid. MS: m/e 182(M"-H2O) , 1 72(M+-CH2Ct £2), 157(M4-CH2CH2CH3), 143, 1 15(base), 101, 84, 55.
IR (film, cm'1): 3476, 2961(vasCH3), 2875(vMCH2), 1725(vasO-C=O), :$ 1220(vasC-O-C).

8.32 grains of target product as a brown liquid were obtained following the procedure as described in Example 27 except that 4.00 ml of j2-methyl-bejizoyl chloride was used to replace benzoyl chloride. MS: m/e, SSOfM*), 379(M4"-1), Ha), 245(M+-CH3C6H4CO2)J 216, 198, 170, 155, 119(base), 91, 77.
Example 3 1 Ethyl l-n-butyl-2-benzoyloxy-cyclopentane carboxylate
10.7 grams of ethyl l-n-butyl-2-hydroxy-cyclopentane carboxylate obtained in Example 16 were diluted with 60ml of methylene chloride. At room temperature and with magnetic stirring, 6.108ml of pyridine was slowly added, then 8.876nl of benzoyl chloride was dropwise added. Upon the completion of me addition, the reaction was continued for 12 hours. Then the procedure as described in Exampb 23 was followed, to give 19.06 g of brown liquid. The brown liquid was purified through column chromatography to give a liquid with a purity, measured by GC, of 96.03%. YieW: 93.7%. MS: 318M OTOtf-OdfcCH,), 261(NT-iH2CH2CH2CH3), 2450^X^012013), 213, 197CM+-C6HsCQ2), 105(base), 77.
Example 32 Ethyl l-n-butyl-2-p-methylbenzoyloxy-cyclopentane carboxylate
6.42 grams of ethyl l-n-butyl-2-hydroxy-cyclopentane carboxylate obtainec in Example 16 were diluted with 60ml of methylene chloride. At rooni temperature irnd with magnetic stirring, 3.66 ml of pyridine was slowly added, then 6.12 ml of 4-methyl-benzoyl chloride was dropwise added. Then the procedure as describee in Example 23 was followed, to give 11.77 g of brown liquid. M$: m/e 332(J/^'), 287(M+-OCH2CH3), 213(Mf-CH3C6H4CO), 197(M+-CH3C6H4C02), 119 (base), 91.
Example 33 Ethyl 1 -n-hexyl-2-benzoyloxy-cyclopentane carboxylate
12.1 grams of ethyl l-n-hexyI-2-hydroxy-cyclopentane carboxylate obtained in Example 17 were diluted with 60ml of methylene chloride. At room temperature with magnetic stirring, 6.108ml of pyridine was slowly added, 1hen 8.876m benzoyl chloride was dropwise added. Then the procedure as described in Exano
23 was followed, to give 18.16 g of yellow liquid MS: 346(M4'), 345(Mf-l), SOlCM'-OCHaCHa), 273(-0022013), 262,
1HNMR(300MHz, CDC13): 0.80(t, 3H, (CH2)5CH3), 1 .05-2.36(m, 16H, 8CH2), 4.17(q, 2H, C02CH2CH3), 5.70(d, 1H, CHO), 7.26-8. 04((m, 5H, QHSCO).
Example 34 Ethyl l-n-hexyl-2-p-methylbenzoyloxy-cyclopentane carboxylate
7.44 grams of ethyl l-n-hexyl-2-hydroxy-cyclopentane carbokylate obtained in Example 17 were diluted with 60ml of methylene chloride. At roonji temperature and with magnetic stirring, 3.66ml of pyridine was slowly added, then 6.12ml of 4-methyl-benzoyl chloride was dropwise added. Then the procedure as described in Example 23 was followed, to give 12.53 g of yellow liquid. MS: m/e 360(M+)> SlSOV^-OCHzCHa), 287(^-0)3012013), 276, 241(k*-ai3C
Example 35 Etfayl 1 -n-bexyl-2-m-mediyibeiizoyloxy-cyclopentane caiboxykte
6.05 grams ( 0. 025ool ) of ethyl l-n4icxyl-2-hydraxy-cydopeiitane carboxylate obtained in Example 17 were diluted with 60ml of methylene chloride.
At room temperature and with magnetic stirring, 3.05ml (0. 0375tool ) of pyridine was slowly added, then 4.99ml of 3-methyl-benzoyl chloride was dropwise added. Then the procedure as described in Example 23 was followed, to give 10.01 g of brown liquid. MS: m/e 361(1^+1), 3600^'), 315(M^-OCH2CH3)S 287(Mf-CO2CH2CH3)J 276, 241(M+-OT3C6H4CO), 225(M+-OJ3C6H4CO2), 195, 1 51, 140, 119(base), 118,91,77.
Example 36 Ethyl l-n-hexyl-2-o-methylbenzoyloxy-cyclopentane carboxylate
9.82 grams of target product as a brown liquid were obtained following t le procedure as described in Example 35 except that 4.96ml of 2-methyl-bemc?yl chloride was used to replace 3-methylbenzoyl chloride. MS: ni/e 3600^'), 315(M+-OCH2CH3), 287(M"-CO2CH2CH3), 276, 225(M4-CH3C6H4CO2), 195, 185, 151, 140, 119(base), 91.
Examples Ethyl l-ethyl-2-acetoxy-cydopentanecarboxylatd
5.58 grams of ethyl l-ethyl-2-hydroxy-cyclopentane carboxylate obtained in Example 15 was diluted with 50ml of methylene chloride. To the solution were added several drops of concentrated sulfiiric acid, then dropwise added 4.32ml of acetic anhydride. The mixture was allowed to react under reflux condition for 2 hours. The reaction mixture was washed with 50 ml of ethyl acetate and 50 ml of water, and organic layer was separated. Then the organic layer was washed with 10% aqueous solution of sodium carbonate twice, then with saline solution to neutrality, and dried over anhydrous magnesium sulfate. Removing solvent gave 5.91g of colorless liquid. Yield after chromatography purification: 83.20%. JMS: m/e 22i(M+'),
Example 38 Ethyl l-ethyl-2-benzoyloxyK^clopentane carboxylate
Ethyl 2-hydbooty-l-hyl-cyclopentaoe carboxylate (4.90g) was diluted is ing 60ml of metfaykae chloride. At room tempecature and with magnetic string, pyricUne (3.22ml) was slowly added, then benzoyl chloride (4.68ml) was drwwise added. Upon the coinpletkm of the addition, the reactwo was continued for 12 bLors. Then solvent was removed, and the residue was extracted using ethyl acetafe and water. Organic layer was washed in rum using 10% hydrochloric acid aqueous solution to pH of about 2, using saline solution to neutrality, using 10% aqueous solution of sodium carbonate for three times, and then using saline solution. to neutrality. The organic layer was dried, and removing solvent gav4 8.86 g liquid. MS: m/e 290(M* ), 261, 216, 185, 168, 139, 105(base), 77.
'HNMR(400MHz,CDCl3): 0.89(t, 3H, CH2CH3), 1.26(t, 3H, 1.72-2.36(m, 8H, 4CH2 ), 4.17(q, 2H, CO2CH2CH3), 5.71(d, 1H, CHO), 7.2&. 04 (m, 5H,
Example 39 Ethyl l-ethyl-2-o-methylbenzoyloxy-cyclopentane carboxylate Ethyl 2-hydroxy-l-ethyl-cyclopentane carboxylate (4.90g) was diluted 60ml of methylene chloride. At room temperature and with magnetic stir^ g, pyridine (3.22ml) was slowly added, then 2-methyl-benzoyl chloride (5.28ml);/ as dropwise added. Upon the completion of the addition, the reaction 12 hours. Then solvent was removed, and the residue was extracted using ethyl acetate and water. Organic layer was washed, in turn, using 10% hydrochloric acid aqueous solution to pH of about 2, using saline solution to neutrality, using 10% aqueous solution of sodium carbonate for three times, and then using saline solution to neutrality. The organic layer was dried, and removing solvent gave 8.99 g of yellow liquid. MS: m/e 304(M+"), 261 , 244, 1 39, 1 1 9(base), 91 .
1HNMR(400MHz,CDCl3): 0.85(t, 3H, CH2CH3), 1.27(t, 3H, C02CH2CH3), 1.71-2.12(m, 8H, 4CH2), 2.36 (s, 3H, o-CHaCCO), 4.18 (q, 2p, CO2CH2CH3), 5.70(d, 1H, CHO), 7.26-7.83(m,
Example 40 Ethyl l-n-propyl-2-benzoyloxy-cyclopentanecarb0xylate
Ethyl 2-hydroxy-l-n-propyl-cyclopentane carboxylate (6.00g)|was diluted us ing 60ml of methylene chloride. At room temperature and with magnetic stirring, pyridine (3.67ml) was slowly added, then benzoyi chloride (5.33ml, 0.045nx>l) was dropwisc added. Upon the compietkin of Ac addition, the reaction Was continued for 12 bouts. Then solvent was removed, and the residue was extracted using ethyl acetate and water. Oiganic layer wts wished, in turn, using 10% hydrochloric acid aqueous solution to pH of about 2, using saline solution to neutrality, using L 0% aqueous solution of sodium carbonate for three times, and then using saline sckrtion to neutrality. The organic layer was dried, and removing solvenj gave lO.OOg of yellow liquid. MS: m/e 305(M*"+1), 304(M*), 259, 230, 199, 18, 153, 105(bi se), 77.
lHNMR(400MHz,CDC!3): 0.83(t, 3H, CH2CH2CH3), 1.26(t, }H, COzCH^CE*), 1.66-2.37(m, 10H, 5CH2 ), 4.16(q, 2H, C02CH2CH3), 5.71(d, 1HJ CHO), 7.27g .04 (m, 5H,
Example 4 1 Ethyl 1 -n-propyl-2-o-methylbenzoyloxy-cyclopentane carboxjtt G
Ethyl 2-hydroxy-l-n-propyl-cyclopentane carboxylate (6.00g) was diluted^ ing 60ml of methylene chloride. At room temperature and with magnetic stii ^ pyridine (3.66ml) was slowly added, then 2-methyl-benzoyl chloride (5.95m) v^vas dropwise added. Upon the completion of the addition, the reaction was contin^ for 12 hours. Then solvent was removed, and the residue was extracted using t
acetate and water. Organic layer was washed, in turn, using 10% hydrochloric acid aqueous solution to pH of about 2, using saline solution to neutrality, using 10% aqueous solution of sodium carbonate for three times, and then usjtog saline solution to neutrality. The organic layer was dried, and removing solveht gave 9.61 g of yellow liquid. MS: m/e 319(MN- 1), 318(1^), 273, 259, 199, 183, 153, 119(base), 91, 77,
1HNMR(400MHz,CDCl3): 0,86(t, 3H, CH2CH2CH3), 1.26(t, 3H, CO2CH2CH3), 1.60-2.36(m, 10H, 5CH2 ), 2.61 (s, 3H, o-CHaC^CO), 4.17(q, ^H, C02CH2CH3),
5.70(q, 1H, CHO), 7.23 -7.89 (m, 4H, o-CH3C6H4CO).
,
Example 42 Ethyl l-n-propyl-2-m-methylbenzoyloxy-cycloperitanecarboxyiate
Ethyl 2-hydroxy-l-n-propyl-cyclopentane carboxylate (6.00g) was diluted i sing 60ml of methylene chloride. At mom temperature and with magnetic stiring, pyridine (3.66ml) was slowly added, then 3-methyi-benzoyl chloride (6.00ml) xvas dropwise added. Upon the completion of the addition, the reaction Was continued for 12 hours. Then solvent was removed, and the residue was extracted using «t iyl acetate and water. Oigank layer was washed, in tain, using 10% hydrochloric ^ cid aqueous solution to pH of about 2, using saline solution to neutrality, using O% aqueous solution of sodium carbonate for three times, and then using saline sohn ion to neutrality. The organic layer was dried, and removing solvent^ gave 10.05 5 of yellow liquid. MS: m/e 319(MVl), 318(M* ), 273, 259 ,244^ 226, 199, 82, 119(base),91,77.
'HNMR(400MHz,CDa3): 0.85(t, 3H, CH2CH2CH3), 1.26(t, 3H, 1.65-2.33(m, 10H, 5CR2 ), 2.41(s, 3ft m-CHaCeRiCO), 4.17 (q, iH,CO2CH2Q[ 5.70(q, 1H, CHO), 7.26-7.83(m, 4H, m-C
Example 43 Ethyl l-n-propyl-2-p-methylbenzoyloxy-cyclopentanecarboxylat(
Ethyl 2-hydroxy-l-n-propyl-cyelopentane carboxylate (6.00g) was diluted 60ml of methylene chloride. At room temperature and with magnetic pyridine (3.66ml) was slowly added, then 4-methyl-benzoyl chloride (6.12ml)r'as
dropwise added. Upon the completion of the addition, the reaction
Then solvent was removed, and the residue was extracted using
acetate and water. Organic layer was washed, in turn, using 10% hydrochloric acid aqueous solution to pH of about 2, using saline solution to neutrality, using 10% aqueous solution of sodium carbonate for three tunes, and then using saline solution to neutrality. The organic layer was dried, and removing solvent gave 10.41 g of yellow liquid. MS: m/e 319(M*+1), 318(M*'), 317(M+-1), 259, 230, 199, 182, 153, 105(base),77.
'HNMR(400MHz,CDCl3): 0.84(t, 3H, CH2CH2CH3), 1.23(t, 3H, 1.64-2.36(m, 10H, 5CH2), 2.41(s, 3H, p-CHjC^CO), 4.16(q, !2H, 5.69(q, 1H, CHO), 7.23-7.93(m, 4H, p-CH3C6H4CO).
Example 44 Ethyl l-n-butyl-2-m-methylbenzoyloxy-cyclopentanecarboxyiate
Ethyl 2-hydroxy-l-n-butyl-cyclopentane carboxylate (6.42g) was diluted a sing 60ml of methylene chloride. At room temperature and with magnetic stirring, pyridine (3.66ml) was slowly added, then 3-memyi-benzoyl chloride (6.01ml) was dropwise added. Upon the completion of the addition, the reaction was continued for 12 hours. Then solvent was removed, and me residue was extracted using e- thyl acetate and water. Organic layer was washed, in turn, using 10% hydrochloric ;acid aqueous solution to pH of about 2, using saline solution to neutrality, and then using 10% aqueous solution of sodium carbonate for three times, then usfcig saline sob ~t ion to neutrality. The organic layer was dried, and removing solvent gave 11.99gg of brown liquid. MS: m/e 332(1^), 287, 213, 196, 167, 1 19(base), 991
1HNMR(400MHz,CDCl3): 0.82(t, 3H, CHzCHzCHaCHa), 1.26(t, :3H, C02CH2CH3), 1.72-2.1 l(m, 12H, 6CH2 ), 2.41 (s, 3H, m-CHAr^CO), 4.17(q^2H, CO2CH2CH3), 5.69 (q, 1H, CHO), 726-7.83(m, 4H,
Example 45 Ethyl l-n-butyl-2-o-methylbenzoyloxy-cyclopentane carboxylatj The target product as a yellow liquid was obtained according to the procedire:?
described in Example 44 except that 2-methylbenzoyl chloride was used to
3-methylbenzoyl chloride. MS: m/e 332(M"), 287(M+-()CH2CH3),
213(^-^30^00), 197(M+-CH3C6H4CO2), 119 (base), 91.
lHNMR(400MHz,CDCl3):. 0.83(t, 3H} CH2CH2CH2CH 1.26(t,
CO2CH2CH3), 1.66-2.36(m, 12H, 6CH2 ), 2.61 (s, 3H, o-CEbCgHO), 4.17 (
I
C02CH2CH3), 5.70(q, 1H, -CHO), 7.25-7.89 (m, 4H, o-CH3C6H4CO).
Example 46 Ethyl l-iso-butyl-2-benzoyloxy-cyclopentane carboxylate
Ethyl 2-hydroxy-l-iso-butyl-cyclopentane carboxylate (5.00g) was diluted using 60ml of methylene chloride. At room temperature and with magnetic stirring, pyridine (2.85ml) was slowly added, then benzoyl chloride (4,15ml,) was drop wise added. Upon the completion of the addition, the reaction was continued for 12 hours. Then solvent was removed, and the residue was extracted using ethyl acetate and water. Organic layer was washed, in turn, using 10% hydrochloric acid aqueous solution to pH of about 2, using saline solution to neutrality, using 10% aqueous solution of sodium carbonate for three times, and then using Saline solution to neutrality. The organic layer was dried, and removing solvent gave 7.70 g of brown liquid. MS: m/e 319(MN-1), 318
!HNMR(400MHz,CDa3): 0.7Wb0.93(
Example 47 Ethyl l-iso-butyl-2-o-methylbenz»yloxy-cyclopentane carboxykt e
Ethyl 2-hydroxy-l-iso-butyl-cyclopentane carboxylate (S.OOg) was diluted ising 60ml of methylene chloride. At room temperature and with magnetic Stirling, pyridine (2.85ml) was slowly added, men 2-methyl-benzoyl chloride (4.64ml) dropwise added. Upon the completion of the addition, the reaction was continue :for 12 hours. Then solvent was removed, and the residue was extracted using acetate and water. Organic layer was washed, in turn, using 10% hydrochloric aqueous solution to pH of about 2, using saline solution to neutrality, using \r}% aqueous solution of sodium carbonate for three times, and then using saline soiut on to neutrality. The organic layer was dried, and removing solvent gave 9.47 ( of brown liquid. MS: m/e 333(1^+1), 332(M*), 28!7(M+-OCH2CT 3),
Example 48 Ethyl l-iso-butyl-2-m-memylbenzoyloxy-cyclopentane carboxylate
Ethyl 2-hydroxy-l- iso-butyl-cyclopentane carboxylate (SiOOg) was diluted using 60ml of methylene chloride. At room temperature and witlj magnetic stirring, pyridine (2.85ml) was slowly added, then 3-methyl-benzoyl chloride (4.68ml} was dropwise added. Upon the completion of the addition, the reaction^ was continued for
i
12 hours. Then solvent was removed, and the residue was extracted using ethyl
acetate and water. Organic layer was washed, in turn, using 10^ hydrochloric acid
aqueous solution to pH of about 2, using saline solution to neutrality, using 10%
aqueous solution of sodium carbonate for three times, and then using saline solution
to neutrality. The organic layer was dried, and removing solvent gave 7.77 g of
yellow liquid. MS: m/e 333(M*+1), 332(M*), 287(Mf-OCH2c4), 258, 213(M*-
gHUCO), 197(M+-CH3C6H4CO2), 119(basc), 91, 77.
Ethyl 2-hydroxy-l-iso-pentyl-cyclopentane carboxylate (6. 4g) was diluted using 60ml of methylene chloride. At room temperature and with magnetic stirring^ pyridine (3.66ml) was slowly added, then benzoyl chloride (5.33|nl) was drojwise added. Upon the completion of the addition, the reaction was continued for 12 bars. Then solvent was removed, and the residue was extracted using ethyl acetate and water. Organic layer was washed, in turn, using 10% hydrochloric acid solution to pH of about 2, using saline solution to neutrality, using 10% solution of sodium carbonate for three times, and then using saline solution to neutrality. The organic
!HNMR(400MHz,CDCl3): 0.77&0.89(d, 6H, CH2CH2CH(C^3)2), 1.27(t, C02CH2CH3), 1.58-2.36(m, 11H, CH2CH2CH(CH3)2, 5CHJ), 4.17(q, CO2CH2CH3), 5.70(d, 1H, CHO), 7.26-8.04(m, 5H, C6HsCO).
Unless otherwise indicated, the synthesis steps in each Example described above were carried out under atmosphere pressure; and the products in Example! 3-49 were purified through chromatography before the spectroscopic analyses.
Examples 50-55 Preparation of solid catalyst component and propylene
polymerization
Preparation of solid catalyst component:
7 grams of spherical MgCl2«2.6C2H5OH particles having an average particle size of 50/im (prepared according to the process as disclosed in Chinese Patent Application CN1330086A) were added into 80ml of hexane to form a suspension. The suspension was cooled to -20°C, and a mixture of 20ml of hexane and 20ml of TiCLt was added thereto. Then the reaction mixture was warmed to 20°C and reaction mixture was heated to 120°C and maintained at that temperature for 2 k urs, then the liquid when hot was filtered off by suction. The solids were washed ^^vith hexane at 50-60°C for three times, and at room temperature for two times, vith the amount of hexane used being 60 ml for each time. Then the spherical solids dried at 40 °C under vacuum for 2 hours, to give a spherical solid catalyst conporient Example 50-55 and electron donor compound used therein were shown in Table
Propylene polymerization:
At room temperature and under nitrogen flow, to a 5L autoclave, which cyclohexyl methyl dimethoxy silane (CHMMS) in hexane (the coneentrai0r of CHMMS was 0.1 mmol/ml), and 9 mg of the solid catalyst components ptep red
i •
above in 10 ml of dry hexane. The autoclave was closed, and 1.5|L of hydro«et.
and 1.5Kg of liquid propylene were then introduced. With, the reactor was heated to 70°C within 5 minutes, and the polymerization was performed at that temperature for 2 hours. After stopping the stirrer and removing unpolymerized propylene monomer, polymer was collected. The polymer was dried at 70°C under vacuum for 2 hours, then weighed to calculate the activity per hour of the catalyst (AC). Isotacticity of the polymer (LI) was measured by boiling niheptane extraction method, and melt index of the polymer (M.I) was measured according to GB/T3682-2000 standard test. Polymerization results are shown in Table 1.
Table 1(Table Removed)It can be seen from the results shown in Table 1 that the carboxylate compounds of the formula (I) according to the invention are suita^ £o* used, as internal electron donor, in the preparation of spherical catalyst for prcp^ 3ie polymerization, and the catalyst is excellent in performance.

Wc claim:
1. A cyclopcntanc carboxylatc compound having a general formula (I):
wherein R' is sclcctcd from thc group consisting of linear or branchcd CI-C2nalkyl,
C3-C~~cycloalkyCl, 6-Caoaryl,C 7-Czoalkaryl and C7-Czoaralkyl;R 2 is sclcctcd from thc group
consisting of linear or branchcd Cz-Czoalkyl, C3-C20cycloalkyl, Cs-Czoaryl, C7-C20alkaryl,
C7-Czoaralkyl, C4-C~alkylcycloalkyl, C4-C~cycloalkylalkyl, and p-mcthylbcnzyl; and I
selected from the group consisting of lincar or branched Cl-C20alkyl, C3-Caocycloalkyl,
C6-Czoary1, C7-Caoalkaryl and C7-C2oaralkyl.
2. 'I'hc cyclopcntanc carboxylatc compound as claimed in claim 1, whcrcin R' is
CI-Cgalkyl; R ~ scSlcctc d from the group consisting of C2-Cloalkyl, C3-Clocycloalkyl,
C4-Cgalkylcycloalkyl, C4-C~cycloalkylalkyl,C 6-Cloaryl,C 7-Cloalkaryl and C7-Cloaralkyl;a nd
R~ is ~clcctcd from the group consisting of CI-Cloalkyl, C3-C~ocycloalkyl, C6-C~oaryl,
C7-Cloalkaryl and C7-Cloaralkyl.
3. 'fhe cyclopcntane carboxylate compound as claimed in claim I, whcrcin R' is selcctcd
from thc group consisting of methyl, ethyl and iso-butyl; R2 is selected from thc group
consisting of Cz-Cloalkyl, CJ-C8cycloalkyl, C5-C7cycloalkylmethy17 C6-C9aryl, C7-Cloalkaryl,
p-mcthylbcnzyl and C7-Cloaralkyl; and R~ is sclcctcd from the group consisting of CI-C4alkyl,
Cs-Crccycloalkyl, phcnyl, p-methylphcnyl, o-mcthylphenyl, m-mcthylphcnyl and bcnzyl.
4. 'l'hc cyclopcntanc carboxylate compound as claimcd in claim 3, whcrcin R' is sclcctcd
from thc group consisting of Cz-C6alkyl, C5-C8cycloalkyl, C6-Cgaryl, bcnzyl, p-mcthylbcn~yl
and phcnethyl.
5. 'The cyclopentane carboxylate compound as claimed in claim 3, whcrcin R' is methyl or
cthyl; R~ is selected from the group consisting of cthyl, n-propyl, iso-propyl, n-butyl, iso-butyl,
n-pcntyl, iso-pcntyl, n-hexyl, benzyl, p-mcthylbcnzyl and phcnethyl; and R3 is sclcctcd from thc
group consisting of methyl, ethyl, n-propyl, iso-propyl, n-butyl, phenyl, p-mcthylphcnyl,
o-mcthylphcnyl, m-methylphenyl and benzyl.
6. 'l'hc cyclopentane carboxylate compound as claimed in claim 1, which is sclcctcd from
the group consisting of
cthyl 1 -benzyl-2-bcnzoyloxy-cyclopcntanec arboxylate;
cthyl 1 -bcnzyl-2-p-methylbenzoyloxy-cyclopentacna rboxylate;
ethyl 1 -bcnzyl-2-m-mcthylbenzoyloxy-cyclopentancea rboxylate;
cthyl 1 -benzyl-2-o-methylbcnzoyloxy-cyclopentacna rboxylate;
mcthyl I -p-mcthylbcnzyl-2-benzoyloxy-cyclopentancea rboxylate;
methyl 1- p-methylbenzyl-2-p-methylbenzoyloxy-cyclopentancea rboxylatc;
mcthyl 1 -p-methylbenzyl-2-m-methylbcnzoyloxy-cycopentancea rboxylatc;
mcthyl l-p-methylbcnzyl-2-o-methylbenzoyloxy-cyclopentancea rboxylatc;
ethyl 1 -n-butyl-2-bcnzoyloxy-cyclopentane carboxylate;
ethyl 1 -n-butyl-2-p-mcthylbenzoyloxy-cyclopentane carboxylate;
cthyl 1 -n-hcxyl-2-bcnzoyloxy-cyclopcntane carboxylate;
cthyl 1 -n-hcxyl-2-p-mcthylbcnzoyloxy-cyclopcntane carboxylate;
cthyl 1 -n-hexyl-2-m-methyl benzoyloxy-cyclopcntane carboxylatc;
cthyl 1 -n-hcxyl-2-o-mcthylbcnzoyloxy-cyclopentane carboxylate;
cthyl I -ethyl-2-acctoxy-cyclopcntancc arboxylate;
cthyl 1 -ethyl-2-benzoyloxy-cyclopentane carboxylate;
cthyl 1 -ethyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
cthyl 1 -n-propyl-2-benzoyloxy-cyclopentane carboxylate;
ethyl 1 -n-propyl-2-o-methylbenzoyloxy-cyclopentane carboxylate;
ethyl 1 -n-propyl-2-m-mcthylbenzoyloxy-cyclopentane carboxylatc;
ethyl 1 -n-propyl-2-p-methylbenzoyloxy-cyclopentane carboxylate;
cthyl 1 -n-butyl-2-m-mcthylbcnzoyloxy-cyclopentanc carboxylatc;
ethyl 1 -n-butyl-2-o-methylbcnzoyloxy-cyclopentane carboxylate;
ethyl I-iso-butyl-2-benzoyloxy-cyclopentane carboxylate;
cthyl 1 -iso-butyl-2-o-methylbenzoyloxy-cyclopentacna rboxylatc;
cthyl 1 -iso-butyl-2-m-mcthylbcnzoyloxy-cyclopentcaa rboxylatc; and
cthyl 1 -iso-pcnty l-2-bcnzoyloxy-cyclopentane carboxylatc.
7. A process for prcparing the cyclopentanc carboxylate compound as claimcd in any onc
of claims 1-6, comprising, in turn, the steps of
1) synthesizing 2-hydrocarbyl-2-hydrocarbyloxycarbonyl-cyclopcntanol intcr~ncdiatc
having a gcneral formula (11)
wherein R' is sclcctcd from the group consisting of linear or branchcd C~-Cz~alkyl,
C3-C20cycloalkyl, C6-Czoaryl, C7-C20alkaryl and C7-C20aralkylare, and 1t2 is sclcctcd from thc
group consisting of linear or branched Cz-Czoalkyl, C3-C20cycloalkyl, C6-C20aryl, C7-C20alkaryl,
C7-Czoaralkyl, C4-C9alkylcycloalkyl, C4-C9cycloalkylalkyl, and p-methylbenzyl,
by hydrocarbylating 2-oxocyclopcntane carboxylate on a-carbon with a halohydrocarbon R'X,
wherein R2 is as defined above, in the presence of a base and an aprotic solvcnt to form
1-hydrocarbyl-2-oxocyclopentane carboxylate, and then selectively rcducing the
I -hydrocarbyl-2-oxocyclopentane carboxylate to form
2-hydrocarbyl-2-hydrocarbyloxycarbonyl-cyclopentanolo f the formula (11); and
2) synthesizing 1-hydrocarbyl-2-acyloxy-cyclopentane carboxylatc compound (I) by
acylating 2-hydrocarbyl-2-hydrocarbyloxycarbonyl-cyclopentano1o f the formula (11) obtaincd
in step 1) with an acyl halide in the presence of a base and an aprotic solvent, to form thc
corresponding 1- hydrocarby]-2-acyloxy-cyclopentanec arboxylate compound of thc formula (I);
alternatively, by acylating 2-hydrocarbyl-2-hydrocarbyloxycarbonyl-cyclopcntanol of thc
formula (11) with a acid anhydride under acid catalytic action and in the prcscnce of an aprotic
solvcnt , to form corresponding I -hydrocarbyl-2-acyloxy-cyclopcntancc arboxylatc compound
of the formula (I).
8. The process as claimcd in claim 7, whcrein the process has at lcast onc of thc following
features:
- in the step l), the base uscd is selected from the group consisting of alkali mctal, alkalinc
carth metal, hydridc of alkali mctal or alkalinc earth metal, carbonatcs of alkali lnctal or
alkalinc carth metal, and combination thcreof; and
- in the step l), the aprotic solvcnt is selcctcd from the group consisting of acctonc,
dimcthyl sulfoxide, N,N-dimethyl formamidc, tetrahydrofuran, pentane, hcxanc, bcnzcnc,
toluene, xylcnc, and combination thcrcof.
9. 'fhc proccss as claimcd in claim 8, whcrein the proccss has at least onc of thc following
features:
- in the step I), thc aprotic solvcnt is polar solvent N, N-dimethyl formamidc, and
- in the step I), the base is a carbonate of alkali metal.
10. 'The process as claimcd in claim 7, wherein in the step I), bcnzyl tricthyl ammonium
chloride or tetra-n-butyl ammonium bromide or combination thereof as phase-transfer catalyst
is used when the halohydrocarbon used in the hydrocarbylation on a-carbon is a branchcd or
cyclic group-containing haloalkanc.
11. 'I'hc proccss as claimcd in claim 7, wherein in thc stcp I),
I-hydrocarbyl-2-oxocyclopcntanc carboxylate is rcduced with a reducing agcnt, which is
selcctcd from the group consisting of lithium borohydride, sodium borohydridc, potassium
borohydride, zinc borohydride, aluminum alkoxides, and combination thcrcof, in an alcoholic
solvcnt.
12. 'I'hc process as claimed in claim 11, wherein the reducing agcnt and thc solvcnt arc
respcctivcly sodium borohydridc and methanol; or aluminum isopropoxidc and isopropanol.
13. The proccss as claimcd in claim 7, wherein the 1-hydrocarbyl-2-oxocyclopcntanc
carboxylate is selectively rcduced under conditions of catalytic hydrogenation, with thc uscd
catalyst being sclcctcd from thc group consisting of nickcl-containing catalysts,
palladium-containing catalysts, Adams' catalyst, and ruthcnium-containing catalysts.
14. 'I'he process as claimcd in claim 7, wherein thc process has at lcast onc of the
following fcaturcs:
- in the stcp 2), thc base is selected from the group consisting of pyridinc, tricthylaminc,
and combination thereof; and
- in thc stcp 2), the aprotic solvent is selected from the group consisting of pyridinc,
tetrahydrofuran, methylcnc chloride, chloroform, pcntane, hexanc, bcnzcnc, tolucnc, xylcnc,
and combination thereof.
15. 'l'he proccss as claimed in claim 7, wherein the process has at least onc of thc
following fcaturcs:
- in thc hydrocarbylation on a-carbon of the step I), molar ratio of the 2-oxocyclopcntanc
carboxylate to the halohydrocarbon is in a rangc of from 1 : 0.5 to 1 : 5, and
- in the hydrocarbylation on a-carbon of the stcp l), molar ratio of the 2-oxocyclopcntanc
carboxylatc to thc base is in a rangc of from 1 : 0.5 to 1 : 5.
16. ?'he process as claimcd in claim 7, wherein the process has at lcast one of thc
following features:
- in the hydrocarbylation on a-carbon of the step l), reaction pressurc is in a rangc of
from atmosphere pressurc to 3 atm,
- in the hydrocarbylation on a-carbon of the step I), reaction tcmpcraturc is in a rangc of
from I0 to 190 OC, and
- in the hydrocarbylation on a-carbon of the step I), reaction timc is in a rangc of from 1
to 24 hours.
17. l'hc proccss as claimed in claim 1 I, wherein the process has at lcast onc of thc
following fcaturcs:
- in the rcduction reaction of the step l), molar ratio of the
I -hydrocarbyl-2-oxocyclopcntanc carboxylate to the rcducing agent is in a rangc of from 1 : 0.5
to 1 : 2;
- in the reduction rcaction of the step l), rcaction pressure is in a rangc of from
atmosphere pressure to 3 atm;
- in the reduction reaction of the step l), reaction temperature is in a range of from -20 to
100 "C; and
- in the reduction rcaction of the step l), reaction time is in a range of from 0.1 to 10
hours.
18. 'The process as claimed in claim 7, wherein the reduction of the step 1) is carried out
under conditions of catalytic hydrogenation, wherein reaction pressure is in a range of from 1 to
10 atm; rcaction temperature is in a range of from 0 to 200 "C; rcaction time is in a rangc of
from 0.5 to 24 hours; the solvent is selected from the group consisting of alcohols, ethers, esters,
and combination thereof; and catalyst is used in an amount of from 0.1 to 5 percent by molc
with respect to the reactant 1- hydrocarbyl-2-oxocyclopentanec arboxylate.
19. 'I'he process as claimed in claim 7, wherein the process has at least one of thc
following fcaturcs:
- in the step 2), an acyl halide is used as acylating agent, and molar ratio of thc acylating
agent to the intermediate (11) is in a rangc of from I : 1 to 15: 1;
- in the stcp 2), molar ratio of base to thc acylating agent is in a range of from 1 : 1 to 10: 1 ;
- in the stcp 2), reaction temcpcrature is in a range of from -20 to 200°C; and
- in the stcp 2), rcxtion pressurc is in a rangc of from atmosphere pressurc to 3 atm.